MetaEfficient

Solar Tubes: Very Efficient Heating

by Justin Thomas • January 22, 2005

Apricus makes a unique solar hot water heater which is 30-40% more efficient than flat plate solar systems.

The secret to the performance is the use of cylindrical evacuated glass tubes to absorb the heat from the sun. Because the tubes are cylindrical, there is always a surface area that is perpendicular to the sun.

The tubes also house a vacuum between two layers of glass. Why a vacuum? A vacuum is an excellent insulator. The insulation properties are so good that while the inside of the tube may be 304°F (150°C), the outer tube is cold to touch. This means that solar tube water heaters can perform well even in cold weather when flat plate collectors perform poorly due to heat loss.

Comments 5

After having many different firms in about installing solar evcuated tubes Ive come to the conslusion that they are all out to make a fast buck, however they all say that heating radiators cost a lot less than heating the water. I can see some logic to this as radiators are on less in summer but hot water is used throughout all seasons. They are charging about £8.000 I have been told that if you pay over £4.500 you have been done..its all very confusing for me, can anyone shed some light on this for me?